Object does not show in render (Cycles) (Blender 2.82)
Alright, I hope I can save someone's time and fix their problem if they ever come across the same issue.
Select the object that doesn't render, go into object properties, scroll down to Instancing, select None and then Render Instancer.
I don't know why it changed the setting by itself, I never clicked on this nor did this ever happen to me before after duplicating part of an object. Whatever